1*6ad3df56SEnze Li /* SPDX-License-Identifier: GPL-2.0 */
2*6ad3df56SEnze Li /*
3*6ad3df56SEnze Li * KFENCE support for LoongArch.
4*6ad3df56SEnze Li *
5*6ad3df56SEnze Li * Author: Enze Li <lienze@kylinos.cn>
6*6ad3df56SEnze Li * Copyright (C) 2022-2023 KylinSoft Corporation.
7*6ad3df56SEnze Li */
8*6ad3df56SEnze Li
9*6ad3df56SEnze Li #ifndef _ASM_LOONGARCH_KFENCE_H
10*6ad3df56SEnze Li #define _ASM_LOONGARCH_KFENCE_H
11*6ad3df56SEnze Li
12*6ad3df56SEnze Li #include <linux/kfence.h>
13*6ad3df56SEnze Li #include <asm/pgtable.h>
14*6ad3df56SEnze Li #include <asm/tlb.h>
15*6ad3df56SEnze Li
arch_kfence_init_pool(void)16*6ad3df56SEnze Li static inline bool arch_kfence_init_pool(void)
17*6ad3df56SEnze Li {
18*6ad3df56SEnze Li int err;
19*6ad3df56SEnze Li char *kfence_pool = __kfence_pool;
20*6ad3df56SEnze Li struct vm_struct *area;
21*6ad3df56SEnze Li
22*6ad3df56SEnze Li area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP,
23*6ad3df56SEnze Li KFENCE_AREA_START, KFENCE_AREA_END,
24*6ad3df56SEnze Li __builtin_return_address(0));
25*6ad3df56SEnze Li if (!area)
26*6ad3df56SEnze Li return false;
27*6ad3df56SEnze Li
28*6ad3df56SEnze Li __kfence_pool = (char *)area->addr;
29*6ad3df56SEnze Li err = ioremap_page_range((unsigned long)__kfence_pool,
30*6ad3df56SEnze Li (unsigned long)__kfence_pool + KFENCE_POOL_SIZE,
31*6ad3df56SEnze Li virt_to_phys((void *)kfence_pool), PAGE_KERNEL);
32*6ad3df56SEnze Li if (err) {
33*6ad3df56SEnze Li free_vm_area(area);
34*6ad3df56SEnze Li __kfence_pool = kfence_pool;
35*6ad3df56SEnze Li return false;
36*6ad3df56SEnze Li }
37*6ad3df56SEnze Li
38*6ad3df56SEnze Li return true;
39*6ad3df56SEnze Li }
40*6ad3df56SEnze Li
41*6ad3df56SEnze Li /* Protect the given page and flush TLB. */
kfence_protect_page(unsigned long addr,bool protect)42*6ad3df56SEnze Li static inline bool kfence_protect_page(unsigned long addr, bool protect)
43*6ad3df56SEnze Li {
44*6ad3df56SEnze Li pte_t *pte = virt_to_kpte(addr);
45*6ad3df56SEnze Li
46*6ad3df56SEnze Li if (WARN_ON(!pte) || pte_none(*pte))
47*6ad3df56SEnze Li return false;
48*6ad3df56SEnze Li
49*6ad3df56SEnze Li if (protect)
50*6ad3df56SEnze Li set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT)));
51*6ad3df56SEnze Li else
52*6ad3df56SEnze Li set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT)));
53*6ad3df56SEnze Li
54*6ad3df56SEnze Li preempt_disable();
55*6ad3df56SEnze Li local_flush_tlb_one(addr);
56*6ad3df56SEnze Li preempt_enable();
57*6ad3df56SEnze Li
58*6ad3df56SEnze Li return true;
59*6ad3df56SEnze Li }
60*6ad3df56SEnze Li
61*6ad3df56SEnze Li #endif /* _ASM_LOONGARCH_KFENCE_H */
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